Data preparation is about how to obtain, clean, normalize, and transform the data into an
optimal dataset, trying to avoid any possible data quality issues such as invalid, ambiguous,
out-of-range, or missing values.

(...)

Scrubbing data, also called data cleansing, is the process of correcting or
removing data in a dataset that is incorrect, inaccurate, incomplete,
improperly formatted, or duplicated.

(...)

In order to avoid dirty data, our dataset should possess the following characteristics:

* Correct
* Completeness
* Accuracy
* Consistency
* Uniformity

(...)

**Data transformation**

Data transformation is usually related to databases and data warehouses where values from
a source format are extract, transform, and load in a destination format.

Extract, Transform, and Load (ETL) obtains data from various data sources, performs some
transformation functions depending on our data model, and loads the resulting data into
the destination.

(...)

Some important transformations:

* Text facet and Clustering
* Numeric fact
* Replace

**Data reduction methods**

Data reduction is the transformation of numerical or alphabetical digital information
derived empirically or experimentally into a corrected, ordered, and simplified form.
Reduced data size is very small in volume and comparatively original, hence, the storage
efficiency will increase and at the same time we can minimize the data handling costs and
will minimize the analysis time also.

We can use several types of data reduction methods, which are listed as follows:

Data exploration is essentially looking at the processed data in a graphical or statistical form
and trying to find patterns, connections, and relations in the data. Visualization is used to
provide overviews in which meaningful patterns may be found.

The four types of EDA are univariate nongraphical, multivariate nongraphical, univariate
graphical, and multivariate graphical. The nongraphical methods refer to the calculation of
summary statistics or the outlier detection. In this book, we will focus on the univariate and

(Cuesta, Hector and Kumar, Sampath; 2016)

**Outlier Detection**

Two outlier detection method should be used, initially, for SkData are:

From the galaxy of information we have to extract usable hidden patterns and trends using
relevant algorithms. To extract the future behavior of these hidden patterns, we can use
predictive modeling. Predictive modeling is a statistical technique to predict future
behavior by analyzing existing information, that is, historical data. We have to use proper
statistical models that best forecast the hidden patterns of the data or
information (Cuesta, Hector and Kumar, Sampath; 2016).

SkData, should allow you to format your data to send it to some predictive library
as scikit-learn.

Visualizing results
-------------------

In an explanatory data analysis process, simple visualization techniques are very useful for
discovering patterns, since the human eye plays an important role. Sometimes, we have to
generate a three-dimensional plot for finding the visual pattern. But, for getting better
visual patterns, we can also use a scatter plot matrix, instead of a three-dimensional plot. In
practice, the hypothesis of the study, dimensionality of the feature space, and data all play
important roles in ensuring a good visualization technique (Cuesta, Hector and Kumar, Sampath; 2016).

Quantitative analytics involves analysis of numerical data. The type of the analysis will
depend on the level of measurement. There are four kinds of measurements:

* Nominal data has no logical order and is used as classification data.
* Ordinal data has a logical order and differences between values are not constant.
* Interval data is continuous and depends on logical order. The data has standardized differences between values, but do not include zero.
* Ratio data is continuous with logical order as well as regular intervals differences between values and may include zero.

Qualitative analysis can explore the complexity and meaning of social phenomena. Data for
qualitative study may include written texts (for example, documents or e-mail) and/or
audible and visual data (digital images or sounds).

(Cuesta, Hector and Kumar, Sampath; 2016)

Reproducibility for Data Analysis
---------------------------------

A good way to promote reproducibility for data analysis is store the
operation history. This history can be used to prepare another dataset
with the same steps (operations).

Books used as reference to guide this project:
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